Chain-grate stoker.



F. G. BRITTON.

CHAIN GRAIE STOKER. APPLICAIION FILED DEC-16, 1914.

1,1 92,850; Patented Aug. 1, 1916v 3 SHEETS-SHEET I.

F. G. BRIT'TON.

CHAIN GRATE STOKER:

APPLICATION FILED DEC- 15, 1914.

Patented Aug.- 1; 1916.

3 SHEETS-SHEET 2 III In II a WWW:

F. G. BRITTON.

CHAIN GRAIIE STOKER. APPLICATION man DEC-16, 1914.

1,192,850. Patented Aug. 1,1916.

3 SHEETS-SHEET 3.

side rates being curved.

' UNITED STATES: PATENT omen.

FRANK GUYVER BRITTON, OF YOKOHAMA, J APAN, ASSIGNOR TO BABOOCK & WILCOX COMPANY; OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEY.

CHAIN-GRATE STOKER.

Specification of Letters Patent.

Patented'Aug'. 1, 1916.

Application filed December 16, 1914. Serial No. 877,482.

To all whom itmag concern: V

Be it known that I, FRANK GUYvnR BRIT- TON, a'subject of the King of the United Kingdom of Great Britain and Ireland, and residing at No. 1 Isogo Machi, Yokohama, Japan, have invented a certain new and useful Improvement in Chain-Grate Stoker's, of which the following is a specification.

The subject of this invention is. a central feed fuel distributing'chain grate stoker for land and marine boilers, comprising an endless traveling chain grate composed of connected links formed as grate bars and side grates composed of fire bars arranged at each'side of the said chain grate.

Among the objects of the. invention are saving of labor, economy of fuel, uniformity of feedunder automatic conditions, and perfection of combustion.

In the accompanying drawings, Figure 1 is a part side elevation part longitudinal section showing the improved stoker fitted to an internally tired boiler such as a boiler of the Lancashire or the Cornish type. Fig. 2 is a section on the line 1\,A, Fig. 1, the

showing the relation of the chain grate and the side grates with fittings, plane side grates having been substituted for the curved grates shown in Fig. 2. Fig. 4 is a side elevation of part of the chain grate. Fig. 5 is a longitiidinal section showing the relal ive position of the hopper and the chain grate. Fig. 6 shows alternative constructions of side. grates. showing the grates supporting the fuel.

Referring to the drawings. the stoker comprises an endless traveling chain grate 2 disposed centrally of the/flue and occupy ing about one third of the width of the fire bed. and stationary. 'i. c... non-traveling, grates one on each side of the chain grate, including the necessary fittings and attachments hereinafter referred to.

'lhechaiu grate is led around sprocketwheels 4 at the front end and the drum 5 at the. rear end of the tire bed. The sprocket wheel sha ft 7 and the. drum shaft 6 are fitted in bearing bushes 16 at the front and rear ends respeclively of the stoker frame, the lop of which frame is parallel to the center line of the flue: the bearings being so located that the upper run oftho chain grate is'at a lower level than the top of the side Fig. 3 is a plan Fig. 7 is an end view.

grates at the front end, and is a the same level as the topof the side grates at the rear end, the forward end of the upper run of the chain grate being therefore upwardly inclined in the direction of travel.

The stoker frame comprises members 1 located one on each side of the chain grate, and firmly secured by stays 3.

The side grates are constituted by fire bars 14, which are provided with suitable a1r passages and are supported by bearers 21 at one end and at the other endby the members 1 of the stoker frame. The fire bars 14 of the side gratesmay be curved or 'plane, and set either inclined or horizontal,

curved fire bars being illustrated in Fig. 2 and plane fire bars being illustrated in Fig. 3. The fire bars may be fixed (14 or movable (14) (FigY G) depending on the type top of the frame 1. the bottom of the hopper being of a width equal to that of the chain grate'or to the internal width of the frame 1; 9 denotes a fuel regulating door fitted within the hopper, and 10 a hinged flap door resting on the upper surface .of the chain grate adjacent to the front end thereof and serving to prevent excess air from entering the furnace.

It will be seen that fuel from the hopper falls on to the chain grate at about the lowest point of the upper run'. and travels up-- ward with the chain grate to a point where the latter is at about the level of the inner edges of the side grates. at about which point the surplus fuel falls over on to the side grates until the entire tire bed is completely covered with fuel. Thefucl is burned completely at the rear end of the furnace. the ashes being parted and spread -on to the side grates at the rear end of the'fnrnace by a wedge-shaped or tapered bridge 13. Theashcs formed on the side grates may he raked out through the doors 11pmvided in the flue cover plate 18 beneath the hopper 8. de'red inoperative owing to mechanical troubles, the doors 17 may be opened to per- Should the chain grate be ren- I mit hand firing to be resorted to. i The fuel on the side grates remains stationary and is added to continuously from the central chain grate, the burning fuel on the side grates quickly igniting the incoming green f el on the central chain grate; that is, in ea'ect, a tunnel of burning fuel is formed under which the incoming fuel completes its combustion by the time it arrives at the rear end of the furnace, so that smoke evolved from the incoming fuel is consumed on its way to the chimney flue. By the time the uppermost layer of fuel is consumed asupply of fresh fuel from beneath is scattered on to the side grates, the tunnel being thus main-.

ment of the grate (which travels in the direction of the arrow shown in Fig. 5) can be readily varied by changmg a set off spurwheels, and that the friction clutch allows cally to the fire bed in such manner as to in of slip in the event of any obstruction, thus obviating the possibility of injury to the mechanism.

From the foregoing it will be seen that with a chain gmteconstructed in accordance with the invention the fuel is fed automatisure an efficient progress of combustion, air being prevented from entering the furnace in excess of that quantity which is required for complete combustion. Thus, the combustion" is rendered perfect and the formation of smoke prevented, while the evaporative capacity of the boiler is increased and the fuel consumption diminished. It may also be added that as with the arrangement described complete combustion can be obtained even with rapid firing, the invention is applicable with advantage to boilers of.

the flash type as well as such for meeting greatly.fluctuating demands of steam.

. I claim 1. In a furnace, in combination, two side grates, each grate extending laterally from run being approximately one of two spaced substantially vertical walls liisposed centrally of the furnace, and an endless traveling chain-grate intermediate said vertical walls, the forward portion of the upper-run of said endless grate being inclined upwardly in the direction of travel from below the top of said vertical walls.

2. In ,a furnace, in combination, side grates disposed centrally of the furnace and an endless traveling chain grate arranged between said side grates, the forward portion of the upper run of said endless grate being inclined upwardly in the directioi} of travel, the front end of said upper run bein located below the level of the top of sai side grates, and the rear end of said u per at the levelo the top of said side grates.

3. In a furnace, in combination, spaced side grates disposed centrally of. the furnace, supports on the outer and inner sides of said side grates, the inner supports being substantially vertical walls, an endless traveling chain grate arranged intermediate said vertical walls, and having its upper run inclined upwardly in the direction of travel from below the top of said vertical walls and thereby adapted to carry 12 ward a charge of fuel supported laterally by said vertical walls, to a point above the latter, whereby the fuel is caused to fall onto said side grates.

4. In a furnace, in combination, an endless traveling chain grate, the forward portion of the upper run of which is inclined upwardly in-thc direction of travel, rocking supports on either side of said chain grate, and fire bars dis osed at an' inclination to the horizontal and resting on said supports. 5. In a furnace, in combination, side grates, an endless traveling chain grate arranged between said side grates, and a taper- 'ing bridge member arranged adjacent to the rear end of the furnace and serving to spread the ashes toward said side grates.

In testimony whereof I have signed my lame to this specification in the presence of no subscribing witnesses.

FRANK GUYVER BRITTON. Witnesses: Serrano Sari,-

HIROICHI MiYoRHr. 

